[llvm] [llvm][Docs] Explain how to handle excessive formatting changes (PR #126239)

[David Spickett via llvm-commits]

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@@ -73,15 +73,33 @@ recent commit:
 
   % git clang-format HEAD~1
 
-Note that this modifies the files, but doesn't commit them -- you'll likely want
-to run
+.. note::
+  For some patches, formatting them may add changes that obscure the intent of
+  the patch. For example, adding to an enum that was not previously formatted
+  may result in the entire enum being reformatted. This happens because not all
+  of the LLVM Project conforms to clang-format at this time.
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DavidSpickett wrote:

Done

https://github.com/llvm/llvm-project/pull/126239